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// Copyright (C) 2012 Vicente Botet
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#define BOOST_THREAD_VERSION 4
#include <boost/thread/mutex.hpp>
#include <boost/thread/lockable_adapter.hpp>
#include <boost/thread/externally_locked.hpp>
#include <boost/thread/strict_lock.hpp>
#include <boost/thread/lock_types.hpp>
#include <iostream>
#ifdef BOOST_MSVC
# pragma warning(disable: 4355) // 'this' : used in base member initializer list
#endif
using namespace boost;
class BankAccount
{
int balance_;
public:
void Deposit(int amount)
{
balance_ += amount;
}
void Withdraw(int amount)
{
balance_ -= amount;
}
int GetBalance()
{
return balance_;
}
};
//[AccountManager
class AccountManager: public basic_lockable_adapter<mutex>
{
public:
typedef basic_lockable_adapter<mutex> lockable_base_type;
AccountManager() :
lockable_base_type(), checkingAcct_(*this), savingsAcct_(*this)
{
}
inline void Checking2Savings(int amount);
inline void AMoreComplicatedChecking2Savings(int amount);
private:
/*<-*/
bool some_condition()
{
return true;
} /*->*/
externally_locked<BankAccount, AccountManager > checkingAcct_;
externally_locked<BankAccount, AccountManager > savingsAcct_;
};
//]
//[Checking2Savings
void AccountManager::Checking2Savings(int amount)
{
strict_lock<AccountManager> guard(*this);
checkingAcct_.get(guard).Withdraw(amount);
savingsAcct_.get(guard).Deposit(amount);
}
//]
//#if DO_NOT_COMPILE
////[AMoreComplicatedChecking2Savings_DO_NOT_COMPILE
//void AccountManager::AMoreComplicatedChecking2Savings(int amount) {
// unique_lock<AccountManager> guard(*this);
// if (some_condition()) {
// guard.lock();
// }
// checkingAcct_.get(guard).Withdraw(amount);
// savingsAcct_.get(guard).Deposit(amount);
// guard1.unlock();
//}
////]
//#elif DO_NOT_COMPILE_2
////[AMoreComplicatedChecking2Savings_DO_NOT_COMPILE2
//void AccountManager::AMoreComplicatedChecking2Savings(int amount) {
// unique_lock<AccountManager> guard1(*this);
// if (some_condition()) {
// guard1.lock();
// }
// {
// strict_lock<AccountManager> guard(guard1);
// checkingAcct_.get(guard).Withdraw(amount);
// savingsAcct_.get(guard).Deposit(amount);
// }
// guard1.unlock();
//}
////]
//#else
////[AMoreComplicatedChecking2Savings
void AccountManager::AMoreComplicatedChecking2Savings(int amount) {
unique_lock<AccountManager> guard1(*this);
if (some_condition()) {
guard1.lock();
}
{
nested_strict_lock<unique_lock<AccountManager> > guard(guard1);
checkingAcct_.get(guard).Withdraw(amount);
savingsAcct_.get(guard).Deposit(amount);
}
guard1.unlock();
}
////]
//#endif
int main()
{
AccountManager mgr;
mgr.Checking2Savings(100);
return 0;
}
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